Square.



G. H CALDWELL.

SQUARE.

APPLICATION FILED nun. 1a, 1910.

972,330. L I Patentad Oct. 11, 1910.

wi'bneooco A. ghfa/edl- CHARLES H. CALDWELL, OF PORTLAND, OREGON.

SQUARE.

7 Specification of Letters Patent.

Application filed March 15, 1910. Serial No.

Patented Oct. 11, 1910.

To all whom it may concern:

Be it known that I, CHARLES H. CALDWELL, a citizen of the United States, residing at Portland, in the county of Multnomah and State of Oregon, have invented certain new and useful Improvements in Squares, of which the following is a specification.

This invention comprehends certain new and useful improvements in measuring and drafting instruments or appliances and relates particularly to improvements in carpenters squares.

The invention has for its primary object a simple, strong and durable construction of adjustable square with an improved construction of joint, the parts being so arranged that the tongue may be securely held in rectangular relation to the blade without any danger of an accidental adjustment to other positions.

With this and other objects in view, as will more fully appear as the description proceeds, the invention consists in certain constructions and arrangements of the parts that I shall hereinafter fully describe and claim.

For a full understanding of the invention, reference is to be had to the following description and accompanying drawing in which:

Figure 1 is a perspective view of a square embodying the improvements of my invention; Fig. 2 is an enlarged fragmentary sectional view of the heel portion of the square; Fig. 3 is a face view of the square at the joint, the tongue being arranged at an angle of 15 to the blade; Fig. 4 is a detail perspective View of the locking device employed to secure the tongue firmly in right angular relation to the blade; Fig. 5 is a sectional view on the line 55 of Fig. 1; and, Fig. 6 is a detail perspective view of the devices for preventing the joint screw from working loose in the opening in which it is located.

Corresponding and like parts are referred to in the following description and indicated in all the views of the accompanying drawings by the same reference characters.

Referring to the drawing, B designates the blade and T the tongue of a square con structed in accordance with my invention. These parts are provided at one end with substantially semi-circular laterally projecting extensions 1 which overlap each other as shown, the extension of one part working in a correspondingly shaped recess 2 formed on the complemental part. Each laterally projecting extension 1 is formed on its edge with a curved lip or flange 3 which works in a curved groove 4 on the opposite member, as best indicated in Figs. 1, 3 and 5.

In the present instance, the blade is pivotally connected to the tongue by a screw 5 which passes through and works in registering apertures formed in the overlapping extensions 1, the shank of the screw being formed at one end with a plurality ofrecesses or notches 6 anyone of which is designed to receive a spring latch 7, said latch lying within a groove 8 formed in one face of the tongue and secured at one end therein as by a cross pin 9 indicated in dotted lines in Fig. 3. By this construction and arrangement of parts it is obvious that the screw will be prevented from working loose, and that the joint between the two parts of the square will be at all times maintained in tight condition. Preferably, the kerf 10 of the screw 5 lies entirely within the mar gin of the head of the screw as indicated in Fig. 2, thereby avoiding any tendency to ream out the opening as the screw turns with the tongue when the latter is adjusted to different angular relations with the blade.

In order to securely hold the blade and tongue at right angles to each other, the tongue 2 is formed with a rearwardly extending arm 11 at its heel end, and a preferably hooked keeper 12 is secured to the arm 11 and is designed to enter a recess 13 formed in the adjoining edge of the blade B, for engagement with a cam latch 14 accommodated therein. The latch 14 is formed on one end of a tubular spindle 15 and a screw 16 works in said spindle so as to secure the latter in place. The spindle 15 is provided at one end with an actuating handle 17 countersunk in a recess 18 formed in one face of the blade B. By moving the handle 17 to one end of the recess 18 the latch 14 will release the keeper 12 so as to permit the tongue to be adjusted relative to the blade, and by moving the handle to the opposite end of the recess, the latch will engage the keeper and lock the blade and tongue at right angles to each other.

From the foregoing description in connection with the accompanying drawing, it will be seen that I have provided a very simple, durable and efficient construction of square in which the tongue may be securely held at right angles to the blade, and also easily adjusted to assume different angular relations with the blade, the two parts of the square being so jointed together that all liability of their becoming loose will be precluded.

Having thus described the invention, what is claimed as new is:

A square, comprising a blade and a tongue I pivotally connected together, one of the parts being formed with a rearwardly extending arm, a keeper connected to said arm, the other part being formed in its edge adjoining the arm with a recess, a latch mounted in said recess, a spindle to which the latch is connected, and a handle connected to one end of the spindle, the latch being designed to engage the keeper whereby to hold the parts locked in right angular relation to each other, one of the parts being formed in one face with a recess in which the handle is countersunk.

In testimony whereof, I affix my signature in presence of two witnesses.

CHARLES H. CALDWELL. Witnesses:

W. N. WoonsoN,

FREDERICK S. S'rrrr. 

